The MXR design team took a classic recording studio fixture and stuffed it into a pedalboard-friendly box. The Studio Compressor features Attack, Release, Ratio, Input, and Output controls so you can fine-tune your compression level-from subtle to squashing-right on stage with visual feedback from a bright LED gain-reduction status meter. Constant Headroom Technology provides tons of headroom for clear, transparent performance that's as dynamic as you need it to be. It's all packed into a durable, lightweight aluminum-housing that's the size of a Phase 90. Specifications Input Impedance: 1 MO Output Impedance: 600 O Max Input Level: +14 dBV Max Output Level: +8.5 dBV Frequency ±1 dB, 20 Hz Response : to 20 kHz Noise Floor*: -90 dBV THD**: < 0.5% Gain: 31 dB Compression Ratio: 4:1, 8:1, 12:1, 20:1 Attack Time: 20 µs to 800 µs Release Time: 50 ms to 1.1 s Bypass True: Hardwire Current Draw: LEDs OFF 14 mA LEDs ON 19 mA Power Supply: 9 volts DC